Reversible-feed chain-stitch sewing machine



' 1,618,213 1 1937' ,J. R. MOFFATT REVERSIBLE FEED CHAIN STITCH SEWING MACHINE Filea Sept. 8, 1922 5 Sheets-Sheet 1 1,618,213 9 J. R. MOFFATT REVERSIBLE FEED CHAIN STITCH SEWING MACHINE Filed Sept. 8,. 1922 5 Sheets-Sheet 2 Feb. 22, 1927. if

J. R. MOFFATT REVERSIBLE FEED CHAIN STITCH SEWING MACHINE Filed Sept. 8, 1922 5 Sheets-Sheet 3 Feb 22, J. R. MOFFATT v REVERSIBLE FEED CHAIN STITCH SEWING MACHINE Filed Sept. 8. 1922 5 Sheets-Sheet 4 Feb. 22,1927. 2 13 J. R. MOFFATT REVERSIBLE FEED CHAIN STITCH SEWING MACHINE Filed dept. a. 1922 5 Sheets-Sheet s Patented eb. 22, 1927. v

UNITED STATES v .v 1,618,213 PATENT. orr ca.

JAMES R. MOFFA'IT, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

REVERSIBLE-FEED CHAIN-STITCH SEWING- MACHINE.

App-lication filed September 8, 1922. Serial No. 586,897.

The invention relates to new and useful improvements in chain stitch sewing machines, and more particularly a machine of the above type wherein a thread carrying 6 looper cooperates with a needle beneath the work support.

An object of the invention is to provide a machine of the above type with a stitching mechanism and devices cooperating therewith whereby a lock chain stitch may be" formed, regardless of the direction of the feed of the machine.

A further object of the invention is to provide a machine of the above type wherein a loop positioning linger engages the looper thread between the eye of the looper and the fabric for holding the thread triangle open for the entrance of the needle when the feed is reversed.

These and other objects will in part. be obvious and will in part be hereinafter more fully disclosed.

In the drawings which show by Way of illustration one embodiment of the invention- Figure 1 is a view partly in section and partly infront elevation of a portion of a sewing machine embodying my improvements; Fig. 2 is a view partly in section and partly in end elevation of a portion of said machine:

Fig. 3 is a view of a portion of the parts shown in Fig. 2, but with the feed reversed;

Fig. is a view partly in section and partly in plan of the parts of the forward end-of the machine beneath the work support;

Fig. 5 is a sectional view on the line 55 of Fig. 4:

Fig. 6 is a sectional view on the line (3-6 of Fi 4:

Fig. 7 is a sectional view on the line 77 of Fig. (i:

Fig; 8 is a perspective view of the means for supporting and operating the loop positioning finger:

Fig. 9 is a view more or less diagrammatic and partly in section, showing the needle, fabric, work support, looper and positioning finger;

Fig. ll) is a diagrammatic view in plan showing the needle. looper and positioning finger with the feed in a normal direction;

'treadle controlled mechanism which may be Fig. 11 is a similar view but showing the feed reversed, and

Fig. 12 is a view similar to Fig. 11, but showing the positioning finger as about to engage the looper thread.

The invention is directed broadly to a machine which includes a thread carrying needle and a thread carrying looper which cooperates with said needle in forming lock chain stitches. The stitch forming mech* anism is of the usual construction. Cooperating with the stitch forming mechanism is a loop positioning finger which engages the looper thread between the eye of the looper and the fabric where the looper thread concatenates with the loops of the previous stitch. The machine includes a reversible feed so that the fabric may be fed away from the operator or reversed and fed in a directiontowa'rd the operator. This loop positioning finger engages the looper thread and holds the portion of the looper thread between said finger andthe eye of the looper in a predetermined position regardless of the direction of feed and this insures that the thread triangle, consisting of the looper thread, the looper, and the needle thread loop, shall be properly positioned and held open for the needle to enter. It is understood of course, that if this positioning finger is not .used when the 85 fabric is fed forward toward the operator, the point where the looper thread is attached to the fabric'moves in the same direction as the lateral movement of the looper, and it will be impossible for the needle to get into the needle thread loop or thread triangle if this positioning finger is not used. The reversible feed may be of any desired character, but it preferably consists of a shifted when the treadle is depressed so as to cause the feed toward the operator, and when'said treadle is released, a spring shifts the parts so as to cause the feed to be in a. normal direction, that is, away from the operator. 7

Referring more in detail to the drawings, I have shown my improvements as embod- .ied in a'sewing machine'which includes a supporting bed 1 provided with the usual bearings 2, 2 on which is mounted a work support 3 having a thread plate 4. The

machine is provided with the usual overat its upper end and hanging arm 5 which carries a needle head 6 in which the needle bar 7 recinrocates. Said needle bar is reciprocated by the usual needle lever 8. Mounted in said needle bar is a needle 9. T-hisneedlc is of the thread carrying type. Cooperating with the needle beneath the work support is a thread carrying looper 11. Said looperis mounted on a looper carrier 12 which in turn is pivoted at 13 to a rocking looper support 14. The looper carrier is oscillated on its support by means of a link 15. The support is oscillated in the usual way from the main shaft 16 located beneath the work support. This thread carrying looper moves forward into the needle thread loop and is then moved laterally for its needle avoiding movement and thus cooperates with the needle in making the well known two thread lock chain stitch.

The-, in-aterial is fed across the work support by means of a feed dog 17 The feed dog 17 is carried-by the shank 18 which is mounted in the feed bar 19. The feed bar 19 is fixed at its rear end to a pin 20 which is pivotally supported in the feed rocker 21. The feed rocker 21 is in turn pivoted so as to swing about the center 22 as an axis. The feed bar is raised and lowered bv means of an eccentric 23 shown in dotted lines in Fig. 4. This eccentric is carried by the main shaft 16. As the main shaft rotates, the feed bar 19 will be raised and loweredcarrying the feed dog into and out of engage ment with the fabric. The feed rocker 1s oscillated for moving the feed dos; back and forth by means of a crank 24 which is adiustably carried by crank disk 25 on the forward end of the shaft 16. A. short stub shaft 26 is mounted in a bracket 27 secured to the bed 1 by suitable screws '28. Fixed to this stub shaft is a rocker arm 29. Said rocker arm 29 is pivoted at 30 to a link 31 which in turn is connected to -the crank 24 so that as the crank rotates. this rocker arm 29 will be oscillated. Said rocker arm is formed witha proiecting slotted plate The slot is indicated at 33. An arm 34 is fixed to the shaft 35 and this shaft 35 carries the rock frame for the feed bar. This arm 34 is connected by means of a link 36 to the slotted plate 32. Said arm is forked a pin 37 passing through the forked ends of the arm rides in the slot'33. It will be noted that the slot 33 extends equally to the right and left of the center 38 which is the axis of the stub shaft 26 carrying the rocker arm Vilhen the link 36 is positioned as shown 1n Fig. 2

. with the upper end of said link at thecxtreme right of the slot 33, the feed is in a normal direction as indicated by the arrow in said figure. \Vhen, however. this link is shifted to the other end of the slot, as shown in Fig. 3, then the directionof feed is in the opposite direction as indicated by the, arrow in said figure. It."'w'i11'. readily be seenthat when the link 36 isshifted from oneend-f of the slot to the other, that the en'dwise stop, the length of feed when reversed, may

be made of the same length or a different length from that when the feed is normal.

As a means for shifting the link36, I

have provided a treadle controlled rock le-.

ver 40 which is mounted to turn freely on the shaft 35, and is connected by means of aflexible chain or the like, indicated by the broken line 41, to a suitable treadle or knee shift. This rock lever hasv an upwardly ex tending arm 42 and'a link 43 connected to said arm 42, and the link 43 serves as a means for shifting said link 36 when said rock lever 40 is oscillated. A spring 44 hearing against an arm 45 formed as a part of the rock lever 40, normally turns the rock lever so as to hold the .parts in the position shown in Fig. 2, and this is the position when the feed-is normal. lVhen the treadle is depressed, then the parts are shifted to the position shown in Fig. 3 and the feed is reversed.

' After the looper has moved forward into the. needle thread loop, it is then moved laterally to the other side of the needle. As the looper moves laterally the feed takes place. and the normal feed is in a direction opposed to the lateral movement of the loopcr. The thread running from the thread eye to the previous stitch in the fabric. will he carried by the feed away from the looper, when the feed is normal. lVith the loopcr moving at right angles to the line of feed as described above, and the feed operating in a normal direction. that is. away from the operator, the thread triangle consisting of the looper thread, liody of the looper, and the needle thread loop, will be properly pos tioned for the needle to enter. and thus the needle enters the needle thread loop and the proper stitch is formed. lVhen, however, the feed is reversed. then the fabric moves toward the operator, and the point of alachnient of the looper thread to the fabric where the previous stitch was formed. is now moved toward the operator, and in the same direction as the lateral movement of the loop'er, and unless some means is provided to hold open the thread triangle. or looper thread loop. the needle will skip the same. I have provided such a means which con ists of a thread positioning tinge'r 46. Said thread positioning finger 46 is providcd with a thread engaging hook end 47 and support 52.

ashank 48 which is ada ted to extend into a sleeve 49 mounted on t is upper end of the carrier 50 which supports and operates said positioning finger. The shank is secured in the sleeve by means of a set screw 51. The carrier 50 is mounted on the upper end of a Said support is provided with a rib 53 which engages a reccss'in the carrier, and a screw 5i serves as a means for securing the parts together. The-support 52 is fixed to a pivot pin and this pivot pin 55 is mounted to oscillate freely. in bears ings 56, 56 carried by a bracket 57. The bracket 57 is secured by bolts 58 to the bed 1. The support 52 is oscillated on its pivotal support by means of a cam 59 mounted on the main shaft- 16. Extending through the support is a short shaft 60. Secured to the end of said short shaft 60 are two arms (51 and (32. These arms engage oppo- The arms are sesite sides of the cam 5!). cured to the. shaft 60 by means of a clamping screw 63. This clamping screw rigidly secures the arms to the shaft 60 but permits the shaft 60 to freely oscillate in the support 52.

The pivotal axis of the support is in a line which cuts the vertical plane containing the feed at an acute angle. The looper cuts said vertical plane containing the feed at right angles as it moves into the needle thread loop. As a result, this support 52 will move so as to carry the thread positioning finger across the path of movement of the looper, and thus causes the hook lTto engage the looper thread.

In Fig.9 of the drawings. the material being stitched is indicated at F, the needle thread at 11-, and the looper thread at. Z. It will be noted that the looper thread between the fabric and the eye of the looper is engaged by the hook of the positioning finger. in this figure, the needle thread loop is around the looper, and this looper positioning finger will hold the looper thread always in a predetermined position regardless of the direction of feed to as to insure that the thread triangle or looper thread loop will be properly positioned for the entrance of the needle. In Fig. .10. l have shown diagrammat-ically the position of the parts with the feed in normal direction and at the time that the needle is about to enter the thread triangle or looper thread loop. The looper 11 has moved laterally for its needle avoiding movement. The previous stitch point is indicated at a. The

threads are carried away fromthe looper by the feed which is in the direction of the arrow shown in this figure. 'i'hc looper thread positioning finger 46 is shown as in engagement with the looper thread although when the feed in a normal direction. this ositioning finger could he dispensed with. its presence, however, does make more certain the opening of the looper thread 100 I for' the needle to get down into the triangle which is clearly shown iii-this Fig. 10.-

In Fig. 11, the feed is reversed as indicated by the arrow and the fabric is moved toward the operator, carrying the concatenations of the'threads at the previous stitch formation to the position shown at s. The positioning finger 46; now becomes the active factor in the spreading of the triangle or looper thread 100 The thread ofthe looper runs from tlie eye of the looper rearwardly to this positioning finger and thence forwardly to the previous stitch. The needle as it comes down will pass between the strand of the looper thread, running from the eyeof the looper to the positioning finger 46 and the body of the loopor, and. thus will enter the thread triangle or the looper thread loop.

In Fig. 12, I have shown in full lines the looper as it is a proaching the forward end of its stroke. l is moved laterally to avoid the loop. The thread positioning finger 46 moves from t..e full line position to the dotted line .po

sition, and as it moves in this path diagonally across the path of the looper, the looper thread will be engaged by the hook 47 of' said positioning finger.

It-will be obvious that other forms of reversible feeds 1na be used from that herein shown and described specifically. The particular invention here is directed to the combination of a reversible feed and a stitch forming mechanism and the associated device which insures the formation of stitches when the feed is reversed.

n dotted lines, the looper It is obvious also that changes in the form of the associated device which insures the form of the stitch with the feed reversed may be changed w'thout departing from the spirit of the invention which is set forth in the appended claims.

Having thus described the invention, what I claim new and desire to secure by Letters-Patent, is-

1. The combination withfeedin mechanism including devices whereby tie direction of feed may be reversed; of stitching mechanism including a thread carrying needle, anda thread carrying looper cooperat iug therewith, and means for engaging the looper thread between the looper eyeand the previous stitch for holding the looper thread so as to insure the needle entering the. looper thread loop when the feed is reversed.

2. The combination with feeding mechanism including devices whereby the direction of fccdmay be reversed; of stitching mechanism including a thread carrying needle. and a thread carrying looper cooperating therewith, a looper thread positioning linger, and means for supporting and moving the same whereby the looper thread between the eye of the looper and the previous stitch is engaged thereby and held so as to insure the needle passing into the looper-thread loop when the feed is reversed.

3. The combination with feeding mecha nism including devices whereby the direction of feed may be reversed; of stitching mechanism including a thread carrying needle. and a thread carrying looper co-operating therewith, a looper thread positioning finger having a hooked end, and means for operating said finger so asto cause said hooked end to engage the looper thread between the eye of the looper and the previous stitch and position said thread so as to in- "sure that the needle will enter the looper thread loop when the feed is reversed.-

4. The combination with feeding mechanism including devices whereby the direction of feed may be reversed; of stitching 1 4 chanism including a thread carrying needle, and a thread carrying looper eo-opcrating therewith, a looper thread positioning finger having a hooked end, means for oscillating said finger in a path crossing the I previous stitch back and forth in a plane at right angles to the line of feed and laterally for a needle avoiding movement, and a looper thread positioning finger movable into engagement with the looper thread between the eye of the looper and the previous stitch for positioning said thread so as to insure that the needle will enter the looper thread loop when the feed is reversed.

(i. The combination with feeding mechanism including devices whereby the direc tion of feed may, be reversed; of stitch forming mechanism including a thread carrying avoiding movement, a

needle, a thread carrying looper moving back and forth in a plane at right angles to the line of feed and laterally for a needle looper thread positioning finger having a hoolred end, and means for moving said finger 1n a direction diagonally across the plane of movement of the looper as it enters theneedle thread loop operating whereby said hooked end engages the looper thread between the eye of the looper and the previous stitch for positioning the same for the entrance of the needle \vlxen the feed is reversed. i

7. The con'ibination with feeding mechanism including devices whereby the direction of feed may be reversed; of stitch forming mechanism including a thread carrying needle, a thread carrying looper moving back and forth in a plane at right angles to the hnc of feed and late ally for a needle avoiding movement, a looper thread positioning tingerfa carrier for said finger, a support for said 02111'161, said support being pivoted so that the finger moves back and forth in a single plane diagonally of the plane of movement of the looper as the looper moves into and out of the needle thread loop, whereby said thread finger engages the looper thread and positions the same so as to insure the needle entering the looper thread loop when the feed is reversed. I

8. The combination of a thread carrying looper; of a looper thread positioning finger cooperating therewith, a support for said finger, means for oscillating said support in a plane diagonally of the path of movement of the looper as the looper moves into and out of the needle thread loop for causing said finger to engage the looper thread.

9. The combination with a thread carr'y ing looper; of a looper thread positioning fin er a sn 3 )ort for said fin er means for pivoting said support whereby the same swings about an axis inclined to the plane of movement of the looper as .it enters the needle thread loop, said looper thread positioning finger having a hooked end for engaging the looper thread between the eye of the looper and the previous stitch.

10. The combination of a thread carryingrlooper, a main shaft, means for oscillating said'looper back and forth in a direction parallel with the shaft, and for moving said looper laterally to avoid the needle, a looper thread positioning finger, a support fol-said linger pivoted to swing in a plane at an acute angle to the plane of moven'ient of the looper as it enters the needle thread loop, a cam on-said main shaft, spaced arms cowithsaid cam, said arms being pivotally connected to said support so as to swing in a plane parallel tothe longitudinal axis of the shaft.

.ln testimony whereof, I athx my signature. v

' JAMES n. 1\{QFFAHT 

